/* $OpenBSD: gost89_keywrap.c,v 1.3 2014/11/09 19:28:44 miod Exp $ */

/*

 * Copyright (c) 2014 Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>

 * Copyright (c) 2005-2006 Cryptocom LTD

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

 * 3. All advertising materials mentioning features or use of this

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    openssl-core@openssl.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR

 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

 * OF THE POSSIBILITY OF SUCH DAMAGE.

 * ====================================================================

 */

#include <string.h>

#include <openssl/opensslconf.h>

#ifndef OPENSSL_NO_GOST

#include <openssl/gost.h>

#include "gost_locl.h"

static void

key_diversify_crypto_pro(GOST2814789_KEY *ctx, const unsigned char *inputKey,

    const unsigned char *ukm, unsigned char *outputKey)

{

  unsigned long k, s1, s2;

  int i, mask;

  unsigned char S[8];

  unsigned char *p;

  memcpy(outputKey, inputKey, 32);

  for (i = 0; i < 8; i++) {

    /* Make array of integers from key */

    /* Compute IV S */

    s1 = 0, s2 = 0;

    p = outputKey;

    for (mask = 1; mask < 256; mask <<= 1) {

      c2l(p, k);

      if (mask & ukm[i]) {

        s1 += k;

      } else {

        s2 += k;

      }

    }

    p = S;

    l2c (s1, p);

    l2c (s2, p);

    Gost2814789_set_key(ctx, outputKey, 256);

    mask = 0;

    Gost2814789_cfb64_encrypt(outputKey, outputKey, 32, ctx, S,

        &mask, 1);

  }

}

int

gost_key_wrap_crypto_pro(int nid, const unsigned char *keyExchangeKey,

    const unsigned char *ukm, const unsigned char *sessionKey,

    unsigned char *wrappedKey)

{

  GOST2814789_KEY ctx;

  unsigned char kek_ukm[32];

  Gost2814789_set_sbox(&ctx, nid);

  key_diversify_crypto_pro(&ctx, keyExchangeKey, ukm, kek_ukm);

  Gost2814789_set_key(&ctx, kek_ukm, 256);

  memcpy(wrappedKey, ukm, 8);

  Gost2814789_encrypt(sessionKey +  0, wrappedKey + 8 +  0, &ctx);

  Gost2814789_encrypt(sessionKey +  8, wrappedKey + 8 +  8, &ctx);

  Gost2814789_encrypt(sessionKey + 16, wrappedKey + 8 + 16, &ctx);

  Gost2814789_encrypt(sessionKey + 24, wrappedKey + 8 + 24, &ctx);

  GOST2814789IMIT(sessionKey, 32, wrappedKey + 40, nid, kek_ukm, ukm);

  return 1;

}

int

gost_key_unwrap_crypto_pro(int nid, const unsigned char *keyExchangeKey,

    const unsigned char *wrappedKey, unsigned char *sessionKey)

{

  unsigned char kek_ukm[32], cek_mac[4];

  GOST2814789_KEY ctx;

  Gost2814789_set_sbox(&ctx, nid);

  /* First 8 bytes of wrapped Key is ukm */

  key_diversify_crypto_pro(&ctx, keyExchangeKey, wrappedKey, kek_ukm);

  Gost2814789_set_key(&ctx, kek_ukm, 256);

  Gost2814789_decrypt(wrappedKey + 8 +  0, sessionKey +  0, &ctx);

  Gost2814789_decrypt(wrappedKey + 8 +  8, sessionKey +  8, &ctx);

  Gost2814789_decrypt(wrappedKey + 8 + 16, sessionKey + 16, &ctx);

  Gost2814789_decrypt(wrappedKey + 8 + 24, sessionKey + 24, &ctx);

  GOST2814789IMIT(sessionKey, 32, cek_mac, nid, kek_ukm, wrappedKey);

  if (memcmp(cek_mac, wrappedKey + 40, 4))

    return 0;

  return 1;

}

#endif